This invention relates to contraceptive sheaths usable during sexual intercourse to prevent conception.
Contraceptive sheaths have been devised for insertion over the male penis to prevent conception during sexual intercourse. Such contraceptive sheaths typically take the form of an elastic tubular sleeve having a bulbous closed end that traps the seminal fluid against escape from the sheath during sexual intercourse.
Typically the contraceptive sheath is formed by dipping a glass mold into a molten bath of latex material. The mold is removed from the bath, so that some of the latex adheres to the mold surface. After drying, the latex is peeled from the mold to form the finished product.
The present invention relates to a contraceptive sheath that has multiple films of latex material, including a latex tubular liner that defines the sheath interior surface, at least one latex film covering the bulbous end of the liner, and a third transparent film covering the entire outer surface of the liner and the latex film (or films). The transparent outer film acts as a sealer to prevent the latex films from peeling or separating from the latex liner.
In one embodiment of the invention there are two latex films between the liner and the transparent sealer film. In another embodiment of the invention there is a single latex film covering the bulbous end of the latex liner. The latex film (or films) strengthen the contraceptive sheath against rupture.
In preferred practice of the invention the liner and the strengthening latex films are formed of contrasting colors, e.g. a blue coloration for the liner, white coloration for the first film, and red coloration for the second film.
The contraceptive sheath of the invention can be formed by a process that involves dipping a glass mold into a latex bath to form the tubular liner, dipping the mold partway into a second latex bath to form the first latex film on the liner outer surface, dipping the mold into a third latex bath to form the second latex film, and dipping the mold into a fourth bath to form an outer transparent covering over the full length of the tubular sheath. The fourth bath is preferably a molten non-viscous plastic.
The dipping operations are performed in rapid sequence, so that the respective latex layers on the mold are only partially dry when the next dipping operation is carried out. Each latex film is bonded to the next film without adhesives or bonding agents.
The respective latex baths have different colorations, to achieve a contraceptive sheath having multiple colorations, e.g. red coloration on the bulbous end of the sheath, white coloration for a minor portion of the sheath tubular length, and blue coloration for a major portion of the sheath tube length.
The multi-layer sheath construction provides redundant protection against rupture or leakage, particularly at the bulbous closed end of the sheath. Also, the multiple coloring of the sheath gives the contraceptive device a distinctive appearance. The transparent film on the sheath outer surface seals the latex layers against peeling or separation from the one piece latex liner.
Further features of the invention will be apparent from the attached drawings and description of a contraceptive sheath embodying the invention.